MUzzle Brake and FPS?

[tinman]

Does this make sense, I have a new Savage 338 Win Mag with a factory muzzle brake on/off type and when closed I am seeing about 100 fps over the open position, so is it like having an extra 2" of barrel?

 

[WildRose]

Does this make sense, I have a new Savage 338 Win Mag with a factory muzzle brake on/off type and when closed I am seeing about 100 fps over the open position, so is it like having an extra 2" of barrel?

Longer barrel, more burn/compression time, makes sense.

That's the same reason why you get much better velocities (all else being equal) from a 26" vs 20-24" bbl.

With your baffles closed you are giving the powder charge two more inches to 'push".